multiple introducer support

author: Faruq (original darcs patches available from
https://tahoe-lafs.org/trac/tahoe-lafs/ticket/68)
color coded multiple introducer status
Merge remote-tracking branch 'killyourtv/68-multi' into david-68work

Here we adapt the multi-introducer patch (ticket #68)
to accomodate the new sequence number and nonce scheme from ticket #1767.
We pass the current_seqnum and current_nonce into IntroducerClient's publish method
instead of that publish method calling the passed in _sequencer function to generate
that sequnum/nonce pair.

Manually resolved conflicts in these files:
	src/allmydata/client.py
        src/allmydata/introducer/client.py
        src/allmydata/introducer/interfaces.py
Leaving these files to Leif's commit to be merged later:
	src/allmydata/test/test_web.py
	src/allmydata/web/root.py
	src/allmydata/web/welcome.xhtml
begin merging kytv/68-multi into ticket68

note: this is a non-working state

Conflicts:
	src/allmydata/client.py
	src/allmydata/test/test_web.py
	src/allmydata/web/root.py
	src/allmydata/web/welcome.xhtml
Merge leif/ticket68 into david-68work

Conflicts:
	src/allmydata/client.py
	src/allmydata/test/test_web.py
	src/allmydata/web/root.py
	src/allmydata/web/welcome.xhtml
Fix syntax error and do not pass sequencer function...
fix allmydata.test.test_web.Web.test_GET_root_html
remove single-introducer censored furl
move introducers list down
temporary fix for stub_client announcements
begin cleaning up html/css for introducers table
Not working commit; missing NativeStorageClient or workaround...
s/server_key/node_key/; multiintro announce works!
display number of connected introducers
censor non-default introducer swissnums
display summary of connected introducers
move introducer list beneath server list
make test_web.Web.test_introducer_status pass
remove sequencer from IntroducerClient clients
pass seq and nonce to publish tests